module ActiveSupport::Benchmark

def self.realtime(unit = :float_second, &block)

`unit` can be any of the values accepted by Ruby's `Process.clock_gettime`.

# => 100.07
ActiveSupport::Benchmark.realtime(:float_millisecond) { sleep 0.1 }

# => 0.10007
ActiveSupport::Benchmark.realtime { sleep 0.1 }

the returned unit is in seconds.
Benchmark realtime in the specified time unit. By default,
:nodoc: 
def self.realtime(unit = :float_second, &block)
  time_start = Process.clock_gettime(Process::CLOCK_MONOTONIC, unit)
  yield
  Process.clock_gettime(Process::CLOCK_MONOTONIC, unit) - time_start
end